Fibers with anionic-cationic finish

ABSTRACT

A textile fiber having a finish coating of compatibilized cationic and anionic components comprising from 0.06 percent to about 3 percent by weight of the fiber, said coating comprising a mixture of (a) an organic anionic surfactant containing at least one alkyl or alkenyl group having from eight to 20 carbon atoms; (b) an organic cationic nitrogen containing surfactant having at least one long chain alkyl or alkenyl group of eight to about 20 carbon atoms; and (c) a compatibilizing quantity of an organic amphoteric nitrogen containing surfactant having at least one alkyl or alkenyl group of eight to 20 carbon atoms.

United States Patent Inventor Thomas J. Proflitt, Jr.

Klnston, N.C.

Appl. No. 751,345

Filed Aug. 9, 1968 Patented Nov. 23, 1971 Assignee E. I. du Pont de Nemours and Company Wilmington, Del.

FIBERS WITH ANIONIC-CATIONIC FINISH 1 Claim, No Drawings References Cited UNITED STATES PATENTS Brown 252/8.8

Primary Examiner-William D. Martin Assistant Examiner.l. E. Miller, Jr. Attorney-E. Leigh Hunt ABSTRACT: A textile fiber having a finish coating of compatibilized cationic and anionic components comprising from 0.06 percent to about 3 percent by weight of the fiber, said coating comprising a mixture of (a) an organic anionic surfactant containing at least one alkyl or alkenyl group having from eight to 20 carbon atoms; (b) an organic cationic nitrogen containing surfactant having at least one long chain alkyl or alkenyl group of eight to about 20 carbon atoms; and (c) a compatibllizing quantity of an organic amphoteric nitrogen containing surfactant having at least one alkyl or alkenyl group of eight to 20 carbon atoms.

E FIBERS WITH ANIONlC-CATIONIC FINISH BACKGROUND OF THE INVENTION 2. Description of the Prior Art In the production of textile fibers, it is customary to apply to the surfaces thereof compositions such as oils or antistats to protect the fiber from damage by contact with machinery and for other reasons such as to give the fiber antistatic properties and to improve its tactile aesthetics. In the trade these compositions are customarily called finishes and are made up of various chemical compounds depending upon their anticipated function. It is frequently desirable to use either cationic or anionic organic surfactants as fiber finishes, each carrying particular properties to dispose the fibers in a desirable manner. The desirability of a water-soluble finish containing both anionic and cationic compounds, for instance, a good anionic antistat and a good cationic softener, is recognized in the trade. However, such a finish composition is not known because of the incompatibility of the two types of ingredients. Upon mixing of the anionic and cationic agents, precipitation and sludgelike formation invariably occurs. Thus, the two agents are called incompatible,"Even when one of the agents is deposited on the fibers and at a later stage in processing the other agent is applied, undesirable solid deposits form and, more than likely, the finished yarn has neither of the desirable properties that each agent was designed to produce.

SUMMARY OF THE INVENTION The invention in its broad scope is defined as a textile fiber containing on its surface from 0.06 percent to 3 percent by weight of a finish comprising an organic anionic, an organic cationic, and an organic amphoteric surfactant, the amount of amphoteric being at least 3 percent of the total solids weight of the finish composition.

The invention in its narrower aspect is defined as a textile fiber having a finish coating of compatibilized cationic and anionic components comprising from 0.06 percent to about 3 percent by weight of the fiber, said coating comprising a mixture of (a) an organic anionic surfactant containing at least one alkyl or alkenyl group having from eight to 20 carbon atoms; (b) an organic cationic nitrogen containing surfactant having at least one long chain alkyl or alkenyl group of eight to about 20 carbon atoms; and (c) a compatibilizing quantity of an organic amphoteric nitrogen containing surfactant having at least one alkyl or alkenyl group of eight to 20 carbon atoms.

DESCRIPTION OF THE PREFERRED EMBODIMENTS It has been unexpectedly found that organic anionic surfactants and organic cationic surfactants are compatibilized in a textile fiber finish by inclusion in the finish bath of at least 3 percent, based on the combined solids weight of the anionic and cationic ingredients, of an organic amphoteric compound. The inclusion of the amphoteric precludes precipitation and sludge formation in the composite finish.

The term organic cationic surfactant refers to a salt that dissociates in solution into an organic cationic surfactant. The organic cationic surfactants included in the chemical combination of this invention are organic nitrogen compounds having at least one long chain alkyl or alkenyl group of eight to about 20 carbon atoms. The most preferred cationic surfactants contain a quaternary nitrogen atom. Typical organic cationic salts useful as surfactants in the practice of this invention comprise:

TABLE I.CATIONIC SURFACTANTS Name Structure e. N-cetyl-N-ethyl- 0 morpholinium-ethyl e sulfate. CH2 CH2 CHaCHzSO4 CH2 Hz N CHsCHz CH2(CH2)u-CH3 b. Cocotrimethyl- CH ammonium chloride. G) e NC 0 C 0 (C12 saturated alkyl) Cl CH CH 0. Cocomethyldi- (hydroxyethy1)- ammonium chloride.

(1. Distearyldimethyl- Same as (b) except replace the coco substituent ammonium chloride. and one CH substituent with stearyl groups.

Same as (b) except replace two methyl groups with hydroxyethyl groups.

TAB LE II.ANIONIC SURFACTANTS Name Structure a. Potassium monoand [0(CH)1OH ]3-x diisooctylphosphate.

0+- P[OK] where X=1 or 2. b. Sodium laurylsullate- Lauryl-OSO;Na. 0. Potassium monoand Same as (a) except substitute a decyl group didecylphosphate. for the isooet vl group. d. Sodium-N-cyclohexyl- N-palmltoyltaurate.

An organic amphoteric surfactant refers to an organic surfactant having both acid and basic properties. The amphoteric surfactants useful in the practice of the present invention are defined as nitrogen-containing organic compounds having at least one alkyl or alkenyl group of eight to 20 carbon atoms. The most preferred contain a carboxyl group or the sodium salt of a carboxyl group. Typical amphoteric surfactants useful in the practice of this invention comprise:

TAB LE III.AMPHOTE RIC S URFAC'IANIS Name Structure a. Disodium N -lauryl-fi-iminodipropionate O O b. N-oleyl-N, N-dimethyl glycine H H CHa\ /C\ Q N /C=O oleyl CH 0 DlSodium N-tallow-fi-imlnodipropionate. .o Same as (a) except lauryl group replaced with a tallow group (mostly stearyl-IB carbon atoms and saturated; and oleyl-18 carbon atoms and unsaturated).

d. l-sodium carboxymethyl-l-sodium oxyethyl-2-nonyl-imidazolinium hydroxide H 99 a-.. e CH CHQ i I l-H 0H e. 1-sodium carboxymethyl-1-sodium carboxymethoxyethyI-Z-undecylimidazolinium H H hydroxide. l

C H C Ha o H2 0 H O 1o 0 NaO-ii CHZO CHzCz CH2( i-ONa f. N-lauryl, N-m yristyl-fi-aminopropionic acid 0 2) 1 CH3 H0( iCHzCH1N g. N -coco-B-aininobuytrle acid H H I l (Mostly lauryl) coco group-N C CH; Fl)

CH2- C- OH The new finish combination is preferably made up in batch plied as a predraw application or postdraw application or even form and then applied to the textile fiber. However, the new as an overlay finish. combination may be applied to the fiber in stepwise fashion; The invention includes any known textile fiber and is parfor example, the anionic agent may be applied to the fiber at ticularly advantageous with fibers based on polymers and one point in the process and, at a later point, the cationic and copolymers of polyethylene terephthalate, nylon, and

amphoteric compounds may be applied. In the former polyacrylonitrile. These fibers have a high volume in the approcess, it is preferable to avoid mixing the anionic and caparel markets where adequate finishing techniques are detionic ingredients before the amphoteric is admixed. in many manded to prevent the fiber from irritating the skin or from cases, however, the amphoteric destroys the precipitate being excessively electrostatic.

formed on mixing of the anionic and Cationic lngl'edients- The invention will be further illustrated by the following ex- An advantage ofthe new finish is that it is Water-disperstbleamples which illustrate the invention but are not intended to This advantage is noteworthy in that water is inexpensive and b d li it fiv readily available and easy to clean from machine parts, etc.

Preferably, the amphoteric compound is added to a vessel EXAMPLES lXlll containing the required volume of water. Then, the anionic and cationic ingredients are admixed. Usually, concentrations of from I to 20 percent solids of the new finish combination in These examples Show the amount of amPhotelric Compound water are applied to running fib b means f a fi i h necessary to compatibilize the anionic and cationic surfacplicator. Applications to produce a solids content of finish intants Show" in the above tables in propo tions.

gredients on the finished yarn of from 0.06 percent to 3 per- To a beaker containing a volume of water is added an cent based on the total weight of the finished yarn are satisfacamphoten'c surfactant selected from table lll, an anionic surtory. factant selected from table ll and a cationic surfactant The new finish combination or any ingredient thereof may selected from table I. The amount of amphoteric necessary to be applied to textile fibers at any place in the production compatibilize the cationic to anionic is recorded. Results are process. Thus, the combination or any part thereof can be apas follows:

Finish solution Amphoteric concentration surfactant (percent from solids in Table III water) Anionic surfactant Table II Cationic surfactant Minimum percent by weight I of amphoteric to compatibilize EXAMPLES XIV-XVII These examples show the application of the finish combinations to textile fibers and show improvement in static electricity properties of the fibers resulting thereby.

The static electricity measurements are determined as follows: A Beckman Micro-microammeter Model-5 manufactured by Beckman Instruments Inc., Fullerton, Calif. with a DC potential of 210 volts and a resistance of l megohm is set up. A thin plate of electrically resistant material having four metal prongs mounted perpendicularly at each comer of a 1.25 inch square (3.2 cm. square) thereon is fabricated and connected to the Micro-microammeter in such a way that upon connecting two pairs of prongs (one pair to negative and one pair to positive 210 volts) current will flow in the system when a sample is on the prongs. The yarn to be tested for static electricity is wound on a 3-in. (7.6 cm.) long 2-in. (5.1 cm.) diameter core to a thickness of about /d-ill. (0.64 cm.). The core containing the yarn is placed lengthwise against the four prongs of the electrical system, and the amount of current flowing through the circuit is measured. Knowing the potential and the amount of current, the resistance is calculated and its logarithm is recorded.

The finish compositions are metered onto the yarn from aqueous solution by means of a metering pipette.

Yarns used for these examples are as follows:

1. 70-denier/34-filament polyhexamethyleneadipamide (nylon) having 2 2" turns per inch (0.79'turns/cm.) twist and containing 0.3 percent by weight TiO When finished the finish level on this yarn is 0.5 percent solids finish ingredients based on the weight of the finished yarn.

ll. 70-denier/34-filament polyethylene terephthalate having essentially no twist and containing 0.3 percent TiO in example XVl the yarn is finished to a level of 0.2 percent solids finish ingredients based on the weight of the finished yarn.

Ill. 75-denier/30-filament yam comprising a copolymer of 94 percent acrylonitrile and 6 percent methyl acrylate having 0.3 2" turns per inch (0.12 toms/cm.) twist and 0.4 percent "no, In examples XVll the yarn is finished to a level of 0.2 percent by weight solids finish ingredients based on the weight of the finished yarn.

EXAMPLE XIV value at the same humidity of approximately 16.5 indicating a 75 degree of static electricity unfavorable for a textile fiber.

EXAMPLE XV The same nylon starting material as used for example XIV is 20 covered with a 10 percent aqueous finish composition comprising 10 parts by weight of the amphoteric surfactant of table Ill-a, 10 parts by weight of the cationic surfactant of table l-a and 80 parts by weight of the anionic surfactant of table "-0. The yarn is finished to a level of 0.5 percent by weight solids finish based on the weight of the finished yarn. Log R at 65 percent relative humidity is 7.5.

EXAMPLE XVI The polyethylene terephthalate yarn is coated with a 20 percent by weight aqueous solution comprising the complex anionic surfactant formed by combining 1 1.6 parts by weight of monoand didecyl-phosphoric acids percent mono 50 percent di) with 8.4 parts of triethanolamine, 40 parts by weight of a nonionic surfactant of a 12- to l8-carbon synthetic primary alcohol condensed with polyoxyethylene so that the weight of polyoxyethylene is percent of the total weight of the molecule, and 20 parts of the amphoteric of table llld, and 20 parts by weight of the cationic surfactant of table l-b. Log R value of the finished yarn is 7.5 as compared to a Log R value of 17.2 for an identical yarn containing no finish on its surface.

EXAMPLE XVll The yarn of acrylonitrile and methylacrylate is coated with a 20 percent by weight aqueous solution comprising 10 parts by weight of a cationic surfactant consisting of dicocodimethylammonium chloride, 30 parts by weight of the amphoteric of table lll-a, 10 parts by weight of the anionic used in example XVI and 50 parts by weight of the nonionic surfactant used in example XVI. The yarn is finished to a level of 0.2 percent by weight solids finish based on the total weight of the finished yarn. The Log R value is 11.8 at 20 percent relative humidity as compared to a Log R value of 16.9 for an identical yam having no finish on its surface.

EXAMPLE XVlll This example shows the combination, in a single bath, of cationic and anionic surfactants in a composition containing other ingredients, by use of an amphoteric surfactant.

To a vessel containing a volume of water is added 3 parts, by weight, of the amphoteric of table Ill-a, 27.7 parts, by weight, of a cationic surfactant comprising the reaction product of stearic acid and diethanolamine quaternized with dimethylsulfate; and 69.3 parts of a mixture comprising 16.6 parts of an anionic surfactant comprising sulfated peanut oil partially neutralized with sodium hydroxide, 8.2 parts by weight of to have excellent antistatic and frictional properused as a predraw finish on nylon yarn, and the r comprises including in the composition an organic amphoteric nitrogen-containing group of eight to 20 surfactant being sufficient to prevent surfactants (a) and (b) from precipitating. 

